Chronic rhinosinusitis is a chronic inflammation of the nasal and paranasal cavities. However, the main pathophysiology of these chronic conditions is poorly described and seems to be multifactorial.In the present study, we reviewed the computed tomography (CT) scans of patients with chronic rhinosinusitis to identify a probable association between the anatomical variations and chronic inflammation in the sinonasal region.Prospective study of the axial and coronal CT scans of 206 chronic rhinosinusitis patients between September 2010 and January 2012 was performed.The study population involved 100 males (48.5%) and 106 females (51.4%) with a mean age of 39 years. The ostiomeatal complex was reported patent in 43 subjects and was blocked in 36 patients. The nasal septa were significantly deviated in 117 (56.7%) patients. Turbinate hypertrophy was reported in 55 (26.6%) patients. Retention cyst was observed in 56 (27.1%) participants. Concha Bullosa and polyps were reported in 36 (17.47%) and 38 (18.44%) patients, respectively. Maxillary sinus was the most common site of involvement (67 patients).Our investigation revealed that there is a strong association between the presence of anatomical variations and chronic inflammation in the paranasal sinuses.
Physiologically generated supersaturation and subsequent crystallization of a weakly basic drug in the small intestine leads to compromised bioavailability. In this study, the pH-induced crystallization of cinnarizine (CNZ) in the presence of different polymers was investigated. Inhibitory effect of Eudragit L100 (Eu) on crystallization of CNZ at varying supersaturation ratios was examined. The effect of Eu on the dissolution behavior of CNZ from CNZ/Eu physical mixtures (PMs) and solid dispersions (SDs) was assessed. Results showed that both Eu and hydroxypropyl methylcellulose (HPMC) have a considerable maintenance effect on supersaturation of CNZ but Eu was more effective than HPMC. When Eudragit was used the phenomenon of liquid-liquid phase separation (formation of colloidal phase) was observed at supersaturation ratio of 20 times above the solubility of the drug. PMs showed a higher area under the dissolution curve (AUDC) compared with plain CNZ. In contrast, SDs showed a lower AUDC than plain CNZ. For SDs, the AUDC was limited by the slow release of the drug from Eu in acidic pH which in turn hindered the creation of CNZ supersaturation following the transition of acidic to neutral pH. From these findings, it can be concluded that the ability of the formulation to generate supersaturation state and also maintain the supersaturation is vital for improving the dissolution of CNZ.
Chalcogenide phase-change materials such as germanium-antimony-tellurium (GST) are suitable materials for use in tunable plasmonic devices. In this paper, a wideband plasmonic switch consists of gold cross-shaped resonators has been designed and simulated in the near-infrared region. The phase-change material GST makes the structure tunable, and by changing the temperature and switching between amorphous and crystalline states, the best extinction ratio of 14 dB and response time of 46 fs have been obtained at the wavelength of 1228 nm. The equivalent circuit model of the suggested structure has been extracted to verify the numerical results. Moreover, the effects of polarization and incident angles and geometric parameters on the structure performance have been evaluated. The proposed tunable and wideband switch with good switching capability can be used in various optical devices such as modulators, logic gates, and optical integrated circuits.
In this paper, we present a GST‐based wideband plasmonic switch. With the excitation of localised surface plasmons and concentration of electric field in the structure, a near‐perfect and wideband absorption is achieved. The switch consists of a GST layer, which acts as a Fabry–Perot cavity. Increasing the temperature and changing the state of GST lead to a high difference between the absorption spectra in amorphous and crystalline states in a wide range of wavelength. Therefore, the switch has a high extinction ratio of 13.71 dB at the wavelength of 1343 nm. Also, the response time of the switch is obtained as 46 fs. The structure has near‐perfect absorption up to the incident angle of about 20°. Moreover, due to the symmetry of structure, the absorption spectrum is independent of polarisation. To show the validity of simulation results, the analytical method of equivalent circuit model is presented. The proposed polarisation‐insensitive switch with high extinction ratio, fast response time and wide bandwidth can be used in photodetectors, plasmonic modulators and logic gates.
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